Could it be a slipping Clutch?

[txvepr]

Wow. glad the sites back .

I am grateful for everyone's information. It turns out it was the Throwout Bearing , I had used the one that was on the 5 speed rather than the one I had on my 4 speed, which probably matches up to my current clutch.

We pulled it again and installed the different one. When I compared the two, it was very hard to tell the difference, measured with calipers and the big difference was the thickness of the bearing sides, and a very little on the throat. Not as apparent as those pics would suggest. Weird the part number was the same on the bearing part.  I saw those pics you posted. 

Once it was back on and buttoned up, the transmission pulls very well! and no slipping. Now to get used to shifting to 5th gear way out there.

I looked all over that 5 speed housing for any identifying numbers and could not find any to determine if mine is a early model or later, other than what the seller told me.

Is there a way to tell just from looking on the outside?

Anyway, I appreciate it, and now feel like I'm at least an expert on how to remove and replace a transmission!! wooot!

 

[EuroDat]

I measured 92mm on mine a couple of years back, and I have seen others quote that number.

[Zed Head]

31 minutes ago, txvepr said:

When I compared the two, it was very hard to tell the difference, measured with calipers and the big difference was the thickness of the bearing sides, and a very little on the throat. Not as apparent as those pics would suggest. Weird the part number was the same on the bearing part.  I saw those pics you posted. 

Is there a way to tell just from looking on the outside?

Anyway, I appreciate it, and now feel like I'm at least an expert on how to remove and replace a transmission!! wooot!

 

It's the distance to where the fork rests, from the bearing contact surface, that matters.  Marked up a picture to illustrate.

The bearing is only pressed on to the collar.  It's replaceable.  That's why the cluthc kits often come with only bearings, and people get screwed up.  The good kits have a collar that matches the pressure plate.

The best way to tell which five speed you have is to measure the 5th speed ratio by turning and counting.  The way to tell early from late is easiest by looking at the exhaust bracket hanger(s), at the very tail-end of the transmission.  Late has only one on the driver's side, early has two, one on each side.

[Mark Maras]

Early trans w-ears on both sides, 5th gear ratio is .864/1. About 7/8ths of a turn.

The later close ratio, one eared trans, 5th gear ratio is .745/1. About 3/4ths of a turn.

[EuroDat]

There are a couple of things that will help you identify which transmission it is.

 

Like Mark already said: Two "Ears" is the early model and one "Ear" is the late model.

The second is the bolt used to secure the speedo. If its above the speedo, its early. If it under the speedo, its the later.

 

The later is often referred to as a "Close Ratio" and there are two varieties. The early "Close Ratio" 1979-80 280ZX has the 0.772 fifth ratio and the 1981-83 280ZX has the 0.742 fifth gear ratio. They are hard to tell apart.

Edit: Trying to get this attaching files under control

Identification FS5W71B.pdf

 

Identification FS5W71B.pdf

Edited December 29, 2015 by EuroDat

[Jeff G 78]

Wow, I never knew that there were two different close-ratio S130 boxes.  I always thought that the close-ratio box came in '81 with the F54 engine.

[LeonV]

On 12/29/2015 at 2:18 PM, Jeff G 78 said:

Wow, I never knew that there were two different close-ratio S130 boxes.  I always thought that the close-ratio box came in '81 with the F54 engine.

You'll get even more muddled-up when you realize that the casting change applies to ALL Nissan 5-speed boxes! A 5-speed with one ear and the speedo bolt at 6 o'clock may not even be a close-ratio gearbox at all.

http://www.gracieland.org/cars/techtalk/gearing2.html

[Zed Head]

I'm pretty sure that, within the Z and ZX family, the exhaust hangers, one or two, will ID the ratio change.  I have a 78 Z 5 speed and an 83 ZX and the casting changes are there.  78 has two, 83 has one.  The speedo cog bolt orientations also.  If you get in to the odd truck or Maxima transmission, maybe not.  

Some of the later 5 speeds are actually shorter overall also though, so you're right - best take a bunch of measurements.  Pretty easy to mark front and back shafts and see what one turn in the front gives in the back.

[EuroDat]

Leon, So true, it gets to be a big list when you include the roadsters, trucks, skylines, & 810 maxima. The FS5W71B close ratio only came in the S130.

One other thing to keep in mind: We are talking about the S130 coupe non turbo version. The 2+2 had the wide ratio box like the 280Z and the turbo had the borg warner T5.

[LeonV]

8 hours ago, Zed Head said:

I'm pretty sure that, within the Z and ZX family, the exhaust hangers, one or two, will ID the ratio change.  I have a 78 Z 5 speed and an 83 ZX and the casting changes are there.  78 has two, 83 has one.  The speedo cog bolt orientations also.  If you get in to the odd truck or Maxima transmission, maybe not.  

Some of the later 5 speeds are actually shorter overall also though, so you're right - best take a bunch of measurements.  Pretty easy to mark front and back shafts and see what one turn in the front gives in the back.

My point was that there is no way to know whether the transmission came from a Z/ZX just by looking at it. I've seen people get screwed over when they're sold a "close-ratio" gearbox judging by the casting only to find out that it's not actually a close ratio box.

[Zed Head]

11 hours ago, LeonV said:

My point was that there is no way to know whether the transmission came from a Z/ZX just by looking at it. I've seen people get screwed over when they're sold a "close-ratio" gearbox judging by the casting only to find out that it's not actually a close ratio box.

I've not seen that.  Two hangers has always been a 3.321 first, one hanger is 3.062 first, with accompanying gear sets.  Maybe the 79-80 ZX 5 speed went to one hanger but kept the 3.321 first.  1979 has all kinds of weirdness.  It's the 260Z of 280ZX's.

I always check everything I look at as soon as possible.  I bought a diff from a guy who is a Z and ZX expert, building engines, drag-racing, works at an import shop,,, and even he got fooled on the ratio because of the car it came in.  He was sure it was 3.9 and it 3.54.  Still bought it.  $50, with CV's.

[EuroDat]

The thread wss originally about a slipping clutch, so I think we have sucessfully hijacked the thread.

The biggest challenge identifying these transmissions is when you have a gearbox that has been removed from the vehicle. Or you don't know the history of the car it came from.

If we are talking about the ZX, it's like 30 years since the last one rolled off the assembly line. A lot can happen in that time.

The difference between the Z and ZX are the "ears" and the speedo adapter bolt position.

If you look at the truck boxes, the Z20, Z22 and Z24 all have the "tilted" transmission. The L20B will fit without any changes but the 1st gear is so low compared will any Zed you would have to notice the difference. The maxima was the same as the 280Z.

I don't know much about the Skylines, but I have heard they were fitted with the FS5C71A and the FS5C71B transmissions.

BTW the "C" means Competition synchros, commonly referred to as the Porsche type steel synchros. The W is for the Warner type bronze synchros.